Installing Window Trim

If you did not notice by the title, today we are talking about installing window trim. That’s right we finally have the trim added to our windows and you should too because it makes all the difference! Here see for yourself…

If you missed the previous post about installing the window jamb extensions, you probably should check that out first. Now onto trimming out those windows. We decided we wanted a simple window trim and we liked these two options.

Option 1: (source)

Option 2: (source)

We decided on the second option because it looked easier to install and our jambs are 5 1/2″ wide, making us not want an overhang on the window sill. But one day I would like to add the cap to the top trim (like the first option).

How to install window trim

TIPS: We purchased 4″ pine boards for all the trim sides (you can use a different size but your measurements will be different). If you would like to save some time down the road, you can paint the boards before installing them. We decided to wait on this step.

UPDATE 10/17: Remember how I said that we used pine well we have used different types of materials and if you are planning on painting the trim, I would recommend using MDF. There are 3 reasons why: 1) it’s an inexpensive material, 2) it gives you a smooth finish, 3) you will not have to worry about the wood grain bleeding through.

To find out the amount of wood you will need, you will measure all the sides of the window (top, bottom, & sides) but you will need to add extra inches to the top and bottom pieces. We wanted an overhang of 1″ from the trim: to do this we measured the top & bottom of the window then add an extra 4 1/2″ to both side ends (you are adding an extra 9″ to both the top & bottom measurements). For example: let’s say the window bottom measured 21″ but we need to add 4 1/2″ to both sides, our piece would then = 30″.

If you are wondering why you are adding only an extra 4 1/2″, it is because the 4″ boards really measure 3 1/2″, funny right… 

The first step to adding the trim was adding the bottom trim piece. We took our measurement of the bottom piece and cut the board at that length (remember to add the extra inches stated above). Then we applied liquid nails to the wood in a zigzag fashion, like picture below: (this picture was from adding the window jambs because I forgot to take a picture when adding the trim)

Then we placed the liquid nails side of the board against the wall, 1/8″ down from the jamb. And nailed it into place. TIP: We marked the board 4 1/2″ in from both sides before adding the liquid nails. This will make it easier to center the board against the window.

Now it is time for the side trim. To get the most accurate measurement, we measured from the bottom trim piece to 1/8″ past the top jamb (just adding about 1/4″ to the previous measurement). Make sure you measure for both the right & left side of the window because they could be different. Then cut the side pieces and top piece (remember to add the extra inches).

After we cut the side pieces & top piece, we then applied liquid nails to the board and placed 1/8″ away from side jamb. Making sure the bottom of the side trim is flush with the bottom trim.

After we finished the side pieces, we added the top trim, again adding liquid nails and placing on top of the side pieces. Sorry picture is blurry.

Now our window trim is all installed.

And as a note, some of our trim and jambs have some gaps but this can be filled in with caulk, this is the next step. And did you see all the nail holes, someone got a little crazy with the nail gun…. I had to remind that person that we have to fill in all those holes. But I am really happy I had help.

So what do you think? The next step is prepping the windows for paint (caulking & filling in the holes). Anyone else adding some trim to their windows? Or would you like to?